Drought responses of selected C₄ photosynthetic NADP-Me and NAD-Me Panicoideae and Aristidoideae grasses
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
- Date Issued: 2015
- Authors: Venter, Nicolaas
- Date: 2015
- Subjects: Aristida , Panicum , Switchgrass , Grasses -- Effect of drought on , Grasses -- Phylogeny , Photosynthesis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4272 , http://hdl.handle.net/10962/d1018549
- Description: Grass species within South Africa show a photosynthetic subtype and phylogenetic response to rainfall gradients, with Panicoideae species (NADP-Me and NAD-Me) inhabiting mesic environments, while Aristidoideae species (NADP-Me) inhabit more arid environments. It is predicted that climate change will alter rainfall patterns within southern Africa, which could have implications for grassland distributions and functional composition. Globally, and in South Africa, species distributions indicates that NAD-Me species have a preference for more arid environments, but this may be complicated by phylogeny as most NAD-Me species belong to the Chloridoideae subfamily. Additionally, differences in the metabolism and energetic requirements of different carboxylation types are expected to confer different ecological advantages, such as drought tolerance, but the role of these different pathways is not well understood. Based on natural distribution and photosynthetic subtype differences, it was hypothesised that Panicoideae NADP-Me species would be less drought tolerant than Panicoideae NAD-Me and Aristidoideae NADP-Me species and that subtypes and lineages would show different drought recovery rates. Furthermore, drought sensitivity would be of a metabolic and not a stomatal origin and plants that maintained favourable leaf water status would be more drought tolerant and recover faster. This was tested experimentally by comparing Panicoideae species (NADP-Me and NAD-Me) and NADP-Me species (Panicoideae and Aristidoideae). Plants were subjected to a progressive 58 day drought period and a recovery phase where gas exchange, chlorophyll fluorescence and leaf water relations were measured at select intervals. In conjunction with this, a rapid drought experiment was performed on Zea mays (NADP-Me: Panicoideae) plants where similar parameters were measured. Photosynthetic drought and recovery responses showed both a subtype and phylogenetic response. Panicoideae species were less drought tolerant than Aristidoideae species, although Panicoideae NAD-Me showed better recovery rates than Panicoideae NADP-Me species, while Aristidoideae species recovered the quickest. Panicoideae NAD-Me and Aristidoideae species maintained higher leaf water status during drought which contributed to the maintenance of PSII integrity and thus facilitated rapid photosynthetic recovery. During drought Panicoideae species showed greater metabolic limitations over Aristidoideae species and for the first time, lower metabolic limitations were associated with osmotic adjustment. This is a novel finding whereby osmotic adjustment and the subsequent maintenance of leaf water are key to preventing metabolic limitations of photosynthesis in C₄ grasses. Results from the Z. mays rapid drought study showed the limitations to photosynthesis were exclusively metabolic and unlikely to be a direct consequence of turgor loss. It was apparent that the response to drought was stronger amongst lineages, as NADP-Me species from different subfamilies showed a significant difference in drought tolerances. Aristidoideae species’ exceptional drought tolerance and predicted increased aridification could favour these species over Panicoideae species under future climates.
- Full Text:
- Date Issued: 2015
Dynamic mitochondrial localisation of STAT3 in the cellular adipogenesis model 3T3-L1:
- Kramer, Adam H, Edkins, Adrienne L, Hoppe, Heinrich C, Prinsloo, Earl
- Authors: Kramer, Adam H , Edkins, Adrienne L , Hoppe, Heinrich C , Prinsloo, Earl
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164885 , vital:41181 , DOI: 10.1002/jcb.25076
- Description: A mechanistic relationship exists between protein localisation, activity and cellular differentiation. Understanding the contribution of these molecular mechanisms is required for elucidation of conditions that drive development. Literature suggests non‐canonical translocation of the Signal Transducer and Activator of Transcription 3 (STAT3) to the mitochondria contributes to the regulation of the electron transport chain, cellular respiration and reactive oxygen species production. Based on this we investigated the role of mitochondrial STAT3, specifically the serine 727 phosphorylated form, in cellular differentiation using the well‐defined mouse adipogenic model 3T3-L1.
- Full Text:
- Date Issued: 2015
- Authors: Kramer, Adam H , Edkins, Adrienne L , Hoppe, Heinrich C , Prinsloo, Earl
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164885 , vital:41181 , DOI: 10.1002/jcb.25076
- Description: A mechanistic relationship exists between protein localisation, activity and cellular differentiation. Understanding the contribution of these molecular mechanisms is required for elucidation of conditions that drive development. Literature suggests non‐canonical translocation of the Signal Transducer and Activator of Transcription 3 (STAT3) to the mitochondria contributes to the regulation of the electron transport chain, cellular respiration and reactive oxygen species production. Based on this we investigated the role of mitochondrial STAT3, specifically the serine 727 phosphorylated form, in cellular differentiation using the well‐defined mouse adipogenic model 3T3-L1.
- Full Text:
- Date Issued: 2015
E-commerce: the challenge of virtual permanent establishments
- Adlkofer, Michelle Leigh, Venter, Michelle
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
- Date Issued: 2015
- Authors: Adlkofer, Michelle Leigh , Venter, Michelle
- Date: 2015
- Subjects: Organisation for Economic Co-operation and Development , Electronic commerce , Electronic commerce -- Taxation , Double taxation -- Treaties , Globalization
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:921 , http://hdl.handle.net/10962/d1020057
- Description: The continued growth of world commerce has led to the advance of the permanent establishment principles. These principles are, however, constantly challenged by the developments of e-commerce. This thesis considers the taxing of a permanent establishment and the influence of e-commerce on the concept of a permanent establishment. In 2000, the Organisation for Economic Co-operation and Development (“OECD”) developed and introduced guidelines on how to deal with e-commerce in the context of a permanent establishment. Since the OECD guidelines on e-commerce were issued, the permanent establishment principles have come under further scrutiny. The latest development came about in 2013 with the release of the Base Erosion and Profit Shifting (“BEPS”) Action Plan. This Action Plan addresses the intention of the OECD to deal with the taxing of the digital economy. With the development of e-commerce and the result of e-commerce creating intangible boundaries between countries, the concept of a virtual permanent establishment has emerged. This has resulted in the need to tax a presence of an enterprise in a jurisdiction where no actual physical connection can be established. Various authors have made suggestions on how to ensure that an economy in which business is being carried on is correctly compensated for in the form of taxes. The source of income is the driving force for the imposition of taxation today. The main goal of this thesis was to explore the alignment of the concepts of a permanent establishment and e-commerce in the digital economy. This study therefore examined the concepts of both permanent establishments and e-commerce, and explored authors’ views and suggestions on how to deal with the inter-related effects of these two concepts. The relevant Action Points in the OECD Action Plan were also considered. , Maiden name: Venter, Michelle
- Full Text:
- Date Issued: 2015
Earnings quality and equity returns : evidence of the accrual anomaly from the South African equity market
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
- Date Issued: 2015
- Authors: Lutchmun, Thashveen
- Date: 2015
- Subjects: Earnings management -- South Africa , Accounting -- Standards
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:915 , http://hdl.handle.net/10962/d1017537
- Description: A key incentive for accounting research is to provide evidence on the usefulness of earnings in making economic decisions. Of particular interest over the last two decades is the issue of the quality of financial reporting, specifically the quality of earnings, given the number of global financial scandals reported during that period. The quality of earnings is driven by the choices, estimates and judgments that the accounting standards make available to managers in order to portray the firm’s economic position and performance in a timely and credible manner. However, this leeway in financial reporting also creates opportunities for earnings management. The objective of this thesis is firstly to establish whether earnings manipulation has had the ability to predict cross-sectional returns in South Africa during the 2007-2014 period. In other words, the purpose of this thesis is to find evidence whether the market reacts to earnings management practices, as measured by accruals, and rewards high earnings quality companies with higher equity returns (a process known as the accrual anomaly). The timeframe selected for the research encompasses the global financial crisis, a period in which accounting manipulation incentives are likely to be strong. Secondly, this study attempts to establish the presence of the accrual anomaly amongst growth and value firms. The motivations for earnings management of the former are expected to be strong. Securities are allocated to portfolios according to accruals and the subsequent equity returns are analysed cross-sectionally to establish the existence of the accrual anomaly and hence assessing the usefulness of earnings manipulation in predicting equity returns. To provide evidence for the presence of the accrual anomaly amongst growth and value shares, securities are independently allocated to portfolios according to their book-to-market ratio and accruals and a cross-sectional analysis is performed on their subsequent equity returns. In order to increase the robustness of the tests, two measures of accruals are used: a balance sheet approach and a cash flow measure. Evidence is provided for the presence of the accrual anomaly among South African listed companies for the balance sheet measure of accruals but not the cash flow approach. Whilst the accrual anomaly is significantly present in a growth-neutral-value construct, statistical significance is not established when growth and value shares are considered individually.
- Full Text:
- Date Issued: 2015
Ecological risk assessment of fisheries on sea turtles in the South Western Indian Ocean
- Authors: Mellet, Bernice
- Date: 2015
- Subjects: Sea turtles -- Indian Ocean Fisheries -- Indian Ocean
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/9957 , vital:26636
- Description: The SWIO is an area of great biodiversity and included in the diverse species that occupy the region are five species of sea turtles that include green turtles, hawksbills, leatherbacks, loggerheads and olive ridleys. Despite considerable conservation efforts at sea turtle rookeries in the South Western Indian Ocean, only green and loggerhead turtle populations have shown an increase in population size in recent years (<10 years), whereas leatherbacks remained stable and hawksbills and olive ridleys declined. This begs the question if fisheries (or other offshore pressures) are responsible for slowing the recovery of these populations in the region, and if so, which specific fisheries are responsible for this trend? Several offshore (mostly industrial) and coastal (mostly artisanal) fisheries overlap with sea turtle distribution at sea. Industrial fisheries that are globally known to have a demonstrable impact on sea turtle populations are longline and to a lesser extent purse seine fisheries, whilst prawn trawl, gillnet and beach seine fisheries are coastal fisheries with a known negative impact on sea turtle populations. Holistic conservation strategies should be developed that include both land and sea protection for sea turtle species. It is thus necessary to identify and manage offshore threats including fisheries activities, particularly those fisheries that are showing the highest risk to sea turtle populations. This prompted an investigation into the bycatch rates and mortality of all sea turtle species that occur in the SWIO region in several offshore and coastal fisheries including both industrial (longline, purse seine and prawn trawl) and artisanal (including gillnet and beach seine) fisheries. The specific aims were (i) to identify and quantify the interactions (and if possible mortality) of sea turtle species in fisheries and (ii) to identify vulnerable species/populations to fishing operations using a semi-quantitative Ecological Risk Assessment (ERA) in the form of a Productivity-Susceptibility Analysis (PSA). Published information, online databases and technical reports were used as data sources to establish a database containing essential information regarding fishing effort and sea turtle bycatch in the region. The existing information was used to map fisheries extent and effort within the region, and to perform bycatch calculations. Interactions and mortality rates for sea turtles in five fisheries were quantified using bycatch rates from regional studies. Between 2000 – 2011, industrial longline and purse seine fisheries captured sea turtles at a rate of 4 388 indiv.y-1, with the mortality rate being 189 indiv.y-1. The bulk of these interactions were in the longline industry that captured 4 129 ± 1 376 indiv.y-1, with a corresponding mortality rate of 167 ± 53 indiv.y-1. The most commonly caught species (in longlines) were loggerheads and leatherback turtles, but the greatest impact is expected to be on the leatherback population due to the high interaction rate relative to population size. The bycatch (259 ± 34 indiv.y-1) and mortality (20 ± 2 indiv.y-1) rates of sea turtles in the purse seine fishery was considerably lower than the longline fishery. The purse seine fishery thus does not seem to have a significant impact on sea turtle populations in the SWIO. The impact of all forms of fish aggregation devices were excluded from the analysis as the impacts of these are poorly documented. Coastal prawn trawl, gillnet and beach seine fisheries captured an estimate of between 50 164 - 52 370 indiv.y-1 from 2000-2011. The highest bycatch rate was estimated for gillnet fisheries (40 264 indiv.y-1) followed by beach seine fisheries (9 171 indiv.y-1) and prawn trawl fisheries (at 1089 – 2795 indiv.y-1). The gillnet fishery could be responsible for slowing the recovery rate of green turtle and leatherback populations in the SWIO due to the high capture rates in this fishery compared to the population sizes of the species. Beach seine and prawn trawl fisheries are not expected to be hamper the recovery rate of any of the populations in the SWIO due to the low levels of interactions and low mortality rates compared to the population sizes. There are however very few data available regarding the bycatch of sea turtle species within these fisheries, highlighting the need for further research regarding this. A productivity-Susceptibility Analysis (PSA) was used to evaluate the relative vulnerability of species to fisheries, and is frequently applied in data poor situations. Limited data on sea turtle life history characteristics and population dynamics of species in the SWIO prompted the use of a PSA to determine the species most vulnerable to fisheries in the region. Results of the PSA indicated that gillnet fisheries poses the largest fishery-related threat to sea turtle populations, specifically the green and leatherback populations. The longline fishery that poses a particular threat to the leatherback population in the SWIO is also a particular concern. A cumulative impact assessment (combining fisheries and other threats) indicated that the SWIO leatherback population is extremely vulnerable to the combination of threats that influence this population in the SWIO. Even though individual fisheries may pose a small threat, the cumulative impacts of the fisheries can lead to severe impacts on populations such as slowing the recovery rate of populations. There are however significant data gaps that require attention in order to fully assess the impact of these fisheries on sea turtle populations. Despite the fact that fisheries are not implicated as a mayor reason for the decline in the hawksbill and olive ridley populations in the region, these two species are in decline indicating that there are other factors responsible for the decline not yet identified. It however remains imperative to reduce the mortality from all sources to ensure the continued viability of sea turtle populations in the region.
- Full Text:
- Date Issued: 2015
- Authors: Mellet, Bernice
- Date: 2015
- Subjects: Sea turtles -- Indian Ocean Fisheries -- Indian Ocean
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10948/9957 , vital:26636
- Description: The SWIO is an area of great biodiversity and included in the diverse species that occupy the region are five species of sea turtles that include green turtles, hawksbills, leatherbacks, loggerheads and olive ridleys. Despite considerable conservation efforts at sea turtle rookeries in the South Western Indian Ocean, only green and loggerhead turtle populations have shown an increase in population size in recent years (<10 years), whereas leatherbacks remained stable and hawksbills and olive ridleys declined. This begs the question if fisheries (or other offshore pressures) are responsible for slowing the recovery of these populations in the region, and if so, which specific fisheries are responsible for this trend? Several offshore (mostly industrial) and coastal (mostly artisanal) fisheries overlap with sea turtle distribution at sea. Industrial fisheries that are globally known to have a demonstrable impact on sea turtle populations are longline and to a lesser extent purse seine fisheries, whilst prawn trawl, gillnet and beach seine fisheries are coastal fisheries with a known negative impact on sea turtle populations. Holistic conservation strategies should be developed that include both land and sea protection for sea turtle species. It is thus necessary to identify and manage offshore threats including fisheries activities, particularly those fisheries that are showing the highest risk to sea turtle populations. This prompted an investigation into the bycatch rates and mortality of all sea turtle species that occur in the SWIO region in several offshore and coastal fisheries including both industrial (longline, purse seine and prawn trawl) and artisanal (including gillnet and beach seine) fisheries. The specific aims were (i) to identify and quantify the interactions (and if possible mortality) of sea turtle species in fisheries and (ii) to identify vulnerable species/populations to fishing operations using a semi-quantitative Ecological Risk Assessment (ERA) in the form of a Productivity-Susceptibility Analysis (PSA). Published information, online databases and technical reports were used as data sources to establish a database containing essential information regarding fishing effort and sea turtle bycatch in the region. The existing information was used to map fisheries extent and effort within the region, and to perform bycatch calculations. Interactions and mortality rates for sea turtles in five fisheries were quantified using bycatch rates from regional studies. Between 2000 – 2011, industrial longline and purse seine fisheries captured sea turtles at a rate of 4 388 indiv.y-1, with the mortality rate being 189 indiv.y-1. The bulk of these interactions were in the longline industry that captured 4 129 ± 1 376 indiv.y-1, with a corresponding mortality rate of 167 ± 53 indiv.y-1. The most commonly caught species (in longlines) were loggerheads and leatherback turtles, but the greatest impact is expected to be on the leatherback population due to the high interaction rate relative to population size. The bycatch (259 ± 34 indiv.y-1) and mortality (20 ± 2 indiv.y-1) rates of sea turtles in the purse seine fishery was considerably lower than the longline fishery. The purse seine fishery thus does not seem to have a significant impact on sea turtle populations in the SWIO. The impact of all forms of fish aggregation devices were excluded from the analysis as the impacts of these are poorly documented. Coastal prawn trawl, gillnet and beach seine fisheries captured an estimate of between 50 164 - 52 370 indiv.y-1 from 2000-2011. The highest bycatch rate was estimated for gillnet fisheries (40 264 indiv.y-1) followed by beach seine fisheries (9 171 indiv.y-1) and prawn trawl fisheries (at 1089 – 2795 indiv.y-1). The gillnet fishery could be responsible for slowing the recovery rate of green turtle and leatherback populations in the SWIO due to the high capture rates in this fishery compared to the population sizes of the species. Beach seine and prawn trawl fisheries are not expected to be hamper the recovery rate of any of the populations in the SWIO due to the low levels of interactions and low mortality rates compared to the population sizes. There are however very few data available regarding the bycatch of sea turtle species within these fisheries, highlighting the need for further research regarding this. A productivity-Susceptibility Analysis (PSA) was used to evaluate the relative vulnerability of species to fisheries, and is frequently applied in data poor situations. Limited data on sea turtle life history characteristics and population dynamics of species in the SWIO prompted the use of a PSA to determine the species most vulnerable to fisheries in the region. Results of the PSA indicated that gillnet fisheries poses the largest fishery-related threat to sea turtle populations, specifically the green and leatherback populations. The longline fishery that poses a particular threat to the leatherback population in the SWIO is also a particular concern. A cumulative impact assessment (combining fisheries and other threats) indicated that the SWIO leatherback population is extremely vulnerable to the combination of threats that influence this population in the SWIO. Even though individual fisheries may pose a small threat, the cumulative impacts of the fisheries can lead to severe impacts on populations such as slowing the recovery rate of populations. There are however significant data gaps that require attention in order to fully assess the impact of these fisheries on sea turtle populations. Despite the fact that fisheries are not implicated as a mayor reason for the decline in the hawksbill and olive ridley populations in the region, these two species are in decline indicating that there are other factors responsible for the decline not yet identified. It however remains imperative to reduce the mortality from all sources to ensure the continued viability of sea turtle populations in the region.
- Full Text:
- Date Issued: 2015
Ecological sustainability for non-timber forest products: dynamics and case studies of harvesting
- Shackleton, Charlie M, Pandey, Ashok K, Ticktin, Tamara
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433656 , vital:72992 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: There is growing knowledge about and appreciation of the im-portance of Non-timber Forest Products (NTFPs) to rural liveli-hoods in developing countries, and to a lesser extent, devel-oped countries. However, there is also an assumption on the part of policy-makers that any harvesting of wild animal or plant products from the forests and other natural and modi-fied ecosystems must be detrimental to the long-term viability of target populations and species. This book challenges this idea and shows that while examples of such negative impacts certainly exist, there are also many examples of sustainable harvesting systems for NTFPs. The chapters review and pre-sent coherent and scientifically sound information and case studies on the ecologically sustainable use of NTFPs. They also outline a general interdisciplinary approach for assessing the sustainability of NTFP harvesting systems at different scales. A wide range of case studies is included from Africa, Asia and South America, using plant and animal products for food, crafts, textiles, medicines and cosmetics.
- Full Text:
- Date Issued: 2015
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/433656 , vital:72992 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: There is growing knowledge about and appreciation of the im-portance of Non-timber Forest Products (NTFPs) to rural liveli-hoods in developing countries, and to a lesser extent, devel-oped countries. However, there is also an assumption on the part of policy-makers that any harvesting of wild animal or plant products from the forests and other natural and modi-fied ecosystems must be detrimental to the long-term viability of target populations and species. This book challenges this idea and shows that while examples of such negative impacts certainly exist, there are also many examples of sustainable harvesting systems for NTFPs. The chapters review and pre-sent coherent and scientifically sound information and case studies on the ecologically sustainable use of NTFPs. They also outline a general interdisciplinary approach for assessing the sustainability of NTFP harvesting systems at different scales. A wide range of case studies is included from Africa, Asia and South America, using plant and animal products for food, crafts, textiles, medicines and cosmetics.
- Full Text:
- Date Issued: 2015
Ecologically sustainable harvesting of non-timber forest products: Disarming the narrative and the complexity
- Shackleton, Charlie M, Pandey, Ashok K, Ticktin, Tamara
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433670 , vital:72993 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: As introduced at the outset of this book, the need for ecologically sustainable harvesting systems for tens of thousands of non-timber forest products (NTFPs) around the world is a requirement for the conservation of the species concerned, and the lives, livelihoods and economies that depend on those species. Ecological sustainability is not simply a ‘nice to have’, a marketing ploy or a conservation fad. Unsustainable harvesting leads to the decline, sooner or later, of NTFP gene pools, populations and species and hence the livelihoods, and species and ecosystem services dependent upon them. Often the negative impacts on peoples’ lives and incomes are not immediately apparent because they may substitute the diminishing returns from one species by harvesting another species, such as favoured firewood species for less preferred species (Madubansi and Shackleton 2007). However, the second, third or more substitute yields lower returns in quality or quantity (or both) than the most preferred species and so a trajectory of dwindling returns looms, either of the benefits obtained, or increased costs to access the benefits. On the other hand, the concept of an ecologically sustainable yield is relatively easy to grasp (Ticktin Chapter 3). All biological resources are renewable. If the rate of harvest is less than the rate of renewal, then the NTFP species or population should persist in the long term. This simplistic picture needs to be fine-tuned to ensure that there are no exacerbatory or synergistic impacts associated with the direct effects of harvesting (such as changes in browsing patterns or fire behaviour)(Ticktin and Shackleton 2011, Ticktin Chapter 3). Additionally, the effects at broader scales, ie beyond just the target species, need to be also taken into account, such as on pollinators, decomposers, nutrient cycles and the like (Ticktin 2004). But in principle, the definition and measurement of an ecologically sustainable yield is well within the means of modern science for the majority of plant and animal NTFP species.
- Full Text:
- Date Issued: 2015
- Authors: Shackleton, Charlie M , Pandey, Ashok K , Ticktin, Tamara
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/433670 , vital:72993 , ISBN 9781317916130 , https://www.routledge.com/Ecological-Sustainability-for-Non-timber-Forest-Products-Dynamics-and-Case/Shackleton-Pandey-Ticktin/p/book/9781138618251
- Description: As introduced at the outset of this book, the need for ecologically sustainable harvesting systems for tens of thousands of non-timber forest products (NTFPs) around the world is a requirement for the conservation of the species concerned, and the lives, livelihoods and economies that depend on those species. Ecological sustainability is not simply a ‘nice to have’, a marketing ploy or a conservation fad. Unsustainable harvesting leads to the decline, sooner or later, of NTFP gene pools, populations and species and hence the livelihoods, and species and ecosystem services dependent upon them. Often the negative impacts on peoples’ lives and incomes are not immediately apparent because they may substitute the diminishing returns from one species by harvesting another species, such as favoured firewood species for less preferred species (Madubansi and Shackleton 2007). However, the second, third or more substitute yields lower returns in quality or quantity (or both) than the most preferred species and so a trajectory of dwindling returns looms, either of the benefits obtained, or increased costs to access the benefits. On the other hand, the concept of an ecologically sustainable yield is relatively easy to grasp (Ticktin Chapter 3). All biological resources are renewable. If the rate of harvest is less than the rate of renewal, then the NTFP species or population should persist in the long term. This simplistic picture needs to be fine-tuned to ensure that there are no exacerbatory or synergistic impacts associated with the direct effects of harvesting (such as changes in browsing patterns or fire behaviour)(Ticktin and Shackleton 2011, Ticktin Chapter 3). Additionally, the effects at broader scales, ie beyond just the target species, need to be also taken into account, such as on pollinators, decomposers, nutrient cycles and the like (Ticktin 2004). But in principle, the definition and measurement of an ecologically sustainable yield is well within the means of modern science for the majority of plant and animal NTFP species.
- Full Text:
- Date Issued: 2015
Editorial. Perspectives on transformations in learning and education
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387277 , vital:68221 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137656"
- Description: Perspectives on transformations in learning and education
- Full Text:
- Date Issued: 2015
- Authors: Lotz-Sisitka, Heila
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387277 , vital:68221 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137656"
- Description: Perspectives on transformations in learning and education
- Full Text:
- Date Issued: 2015
Educating children presenting with autistic spectrum disorders: exploring parents' experiences
- Authors: McGrath, Wanita
- Date: 2015
- Subjects: Autistic children -- Education , Autistic children
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/10265 , vital:26647
- Description: According to Pienaar and Raymond (2013, p.10) learners with disabilities have historically experienced the most serious exclusion from learning. The worldwide call for inclusive education prompted South Africa to develop the White Paper 6 (WP6) (2001, p.18) which clearly states that for Inclusive Education to be successfully implemented in South Africa, there has to be an acknowledgement that all children and youth can learn. The implementation of WP6 therefore not only benefits learners with special educational needs, but all South African learners by implementing "a more flexible system of education that focuses on removing barriers to learning and creating learning-friendly environments" (Pienaar and Raymond, 2013, pp. 10-11). However, a great disparity exists in what is proposed in official documents such as WP6 and what parents of children with barriers to learning actually experience within schools. This phenomenological study employed memory work, drawings and focus group discussions with four purposively selected parents to explore parents’ experiences of the education of their children who are on the Autistic Spectrum. Bronfenbrenner’s Eco-systemic perspective was used to make meaning of the data. The findings show that parents find the education of their autistic children as a stressful and isolating experience because of an unprepared education system. Despite the challenges, the participants also find their experiences to be a journey of personal growth and fulfilment. The study therefore recommends that schools should engage parents of autistic children more actively in order to make inclusion of such children effective. Teachers who are expected to practice inclusivity in schools should be adequately prepared to work with children presenting with ASD through a collaborative effort of the Department of Health and the Department of Education.
- Full Text:
- Date Issued: 2015
- Authors: McGrath, Wanita
- Date: 2015
- Subjects: Autistic children -- Education , Autistic children
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10948/10265 , vital:26647
- Description: According to Pienaar and Raymond (2013, p.10) learners with disabilities have historically experienced the most serious exclusion from learning. The worldwide call for inclusive education prompted South Africa to develop the White Paper 6 (WP6) (2001, p.18) which clearly states that for Inclusive Education to be successfully implemented in South Africa, there has to be an acknowledgement that all children and youth can learn. The implementation of WP6 therefore not only benefits learners with special educational needs, but all South African learners by implementing "a more flexible system of education that focuses on removing barriers to learning and creating learning-friendly environments" (Pienaar and Raymond, 2013, pp. 10-11). However, a great disparity exists in what is proposed in official documents such as WP6 and what parents of children with barriers to learning actually experience within schools. This phenomenological study employed memory work, drawings and focus group discussions with four purposively selected parents to explore parents’ experiences of the education of their children who are on the Autistic Spectrum. Bronfenbrenner’s Eco-systemic perspective was used to make meaning of the data. The findings show that parents find the education of their autistic children as a stressful and isolating experience because of an unprepared education system. Despite the challenges, the participants also find their experiences to be a journey of personal growth and fulfilment. The study therefore recommends that schools should engage parents of autistic children more actively in order to make inclusion of such children effective. Teachers who are expected to practice inclusivity in schools should be adequately prepared to work with children presenting with ASD through a collaborative effort of the Department of Health and the Department of Education.
- Full Text:
- Date Issued: 2015
Educators and learners perceptions on english first additional language speakers use of english as medium of instruction
- Authors: Nqoma, Lungiswa
- Date: 2015
- Subjects: English language -- Study and teaching , English language
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24934 , vital:63678
- Description: This study investigates Educators‟ and learners‟ perceptions on English first additional language speakers‟ use of English as medium of instruction in two primary schools in the East London District. The study made use of a qualitative research method which includes interviews, observation and document analysis (learners‟ books). The uncovered data is analyzed against the background of the socio-economic and historical factors that led to this medium of instruction using content analysis (CA). After the apartheid regime in 1994 and the formation of a new government in 1996, the South African Constitution declared 11 languages in an attempt to encourage multilingualism in the country with each province having its provincial language policy. In the Eastern Cape where the study is conducted the language policy recognizes Xhosa, English, and Afrikaans as the official languages with English as the medium of instruction especially at the intermediate phase. The theoretical and conceptual framework for the study is provided by studies on language policy and planning, English as an international language, and Language as a mediating tool. The findings of the study indicate the crucial role that language of instruction plays in teaching and learning. However, challenges arise when the language of instruction is not the mother tongue. The study indicates dissatisfaction in the use of EMOI as a result of inadequate proficiency in the language of instruction, school environment, lack of resources; and lack of parental support. As a result of the above, some educators resorted to code switching when teaching. Hence, the study sheds light on EFAL learner‟s perspective on both comprehension and the level of educator‟s English skills and whether there is a connection between these two aspects. This resulted to conceivable methods that could be used to improve learner performance, teaching and learning methods and the efficiency of East London District support system. , Thesis (MEd) -- Faculty of Education, 2015
- Full Text:
- Date Issued: 2015
- Authors: Nqoma, Lungiswa
- Date: 2015
- Subjects: English language -- Study and teaching , English language
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24934 , vital:63678
- Description: This study investigates Educators‟ and learners‟ perceptions on English first additional language speakers‟ use of English as medium of instruction in two primary schools in the East London District. The study made use of a qualitative research method which includes interviews, observation and document analysis (learners‟ books). The uncovered data is analyzed against the background of the socio-economic and historical factors that led to this medium of instruction using content analysis (CA). After the apartheid regime in 1994 and the formation of a new government in 1996, the South African Constitution declared 11 languages in an attempt to encourage multilingualism in the country with each province having its provincial language policy. In the Eastern Cape where the study is conducted the language policy recognizes Xhosa, English, and Afrikaans as the official languages with English as the medium of instruction especially at the intermediate phase. The theoretical and conceptual framework for the study is provided by studies on language policy and planning, English as an international language, and Language as a mediating tool. The findings of the study indicate the crucial role that language of instruction plays in teaching and learning. However, challenges arise when the language of instruction is not the mother tongue. The study indicates dissatisfaction in the use of EMOI as a result of inadequate proficiency in the language of instruction, school environment, lack of resources; and lack of parental support. As a result of the above, some educators resorted to code switching when teaching. Hence, the study sheds light on EFAL learner‟s perspective on both comprehension and the level of educator‟s English skills and whether there is a connection between these two aspects. This resulted to conceivable methods that could be used to improve learner performance, teaching and learning methods and the efficiency of East London District support system. , Thesis (MEd) -- Faculty of Education, 2015
- Full Text:
- Date Issued: 2015
Educators'perceptions on the contribution of South African Democratic Teachers' Union to teacher professional development
- Authors: Kwayiba, Xolile Lawrence
- Date: 2015
- Subjects: Teachers' unions Teachers -- In-service training -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6081 , vital:29489
- Description: The purpose of the study was to investigate the educators’ perceptions on the role of the South African Democratic Teachers’ Union (SADTU) in teacher professional development. The study also investigated the Union’s perceived challenges in contributing to teacher professionalism in South Africa, their perceived professional priorities and perceived expectations of teachers. The research genre used for this study was the interpretivism or constructivism paradigm. The qualitative methodology was used and case study employed as the research design of the study. The findings of this study were that SADTU were perceived as militant activists. Their activities were perceived as often very disruptive to education and their role appeared to be more politically focused than educational. They promoted and protected teacher labour rights and interests. However, they had no programme, nor the expertise nor the resources to respond to teachers’ professional development needs. The perceptions about them were that they had minimal or negligible contribution to teacher professional development. SADTU conducted training, but with nothing of value to teacher professional development. The unethical, unconstitutional and professionally non-developmental cadre deployment of SADTU leadership compromised the Union. Another finding was the important role of appropriate continuous professional development programmes in the improvement of the teachers’ own professional development, in the improvement of classroom practices and eventual enhanced learner performance. Inclusive to professional development are educationally good skills and values to colleagues, learners and parents both at school and out of school. Recommendations for SADTU were the: development of a clear programme on Teacher Professional Development; mobilisation of SADTU members towards restoring and enhancing the dignity of the teaching profession; engaging politically in curriculum policymaking to form inclusive professional associations; ending cadre deployment for senior management posts by SADTU leadership; establish development centres for critical maths and science, computers skills and other subjects and resuscitation of teacher colleges.
- Full Text:
- Date Issued: 2015
- Authors: Kwayiba, Xolile Lawrence
- Date: 2015
- Subjects: Teachers' unions Teachers -- In-service training -- South Africa -- Eastern Cape Teachers -- Training of -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: http://hdl.handle.net/10353/6081 , vital:29489
- Description: The purpose of the study was to investigate the educators’ perceptions on the role of the South African Democratic Teachers’ Union (SADTU) in teacher professional development. The study also investigated the Union’s perceived challenges in contributing to teacher professionalism in South Africa, their perceived professional priorities and perceived expectations of teachers. The research genre used for this study was the interpretivism or constructivism paradigm. The qualitative methodology was used and case study employed as the research design of the study. The findings of this study were that SADTU were perceived as militant activists. Their activities were perceived as often very disruptive to education and their role appeared to be more politically focused than educational. They promoted and protected teacher labour rights and interests. However, they had no programme, nor the expertise nor the resources to respond to teachers’ professional development needs. The perceptions about them were that they had minimal or negligible contribution to teacher professional development. SADTU conducted training, but with nothing of value to teacher professional development. The unethical, unconstitutional and professionally non-developmental cadre deployment of SADTU leadership compromised the Union. Another finding was the important role of appropriate continuous professional development programmes in the improvement of the teachers’ own professional development, in the improvement of classroom practices and eventual enhanced learner performance. Inclusive to professional development are educationally good skills and values to colleagues, learners and parents both at school and out of school. Recommendations for SADTU were the: development of a clear programme on Teacher Professional Development; mobilisation of SADTU members towards restoring and enhancing the dignity of the teaching profession; engaging politically in curriculum policymaking to form inclusive professional associations; ending cadre deployment for senior management posts by SADTU leadership; establish development centres for critical maths and science, computers skills and other subjects and resuscitation of teacher colleges.
- Full Text:
- Date Issued: 2015
Effect of conventional and organic orchard floor management practices on arbuscular mycorrhizal fungi in a ‘Cripp’s Pink’/M7 apple orchard soil
- Meyer, André H, Wooldridge, John, Dames, Joanna F
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
- Date Issued: 2015
- Authors: Meyer, André H , Wooldridge, John , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444012 , vital:74178 , https://doi.org/10.1016/j.agee.2015.07.026
- Description: Arbuscular mycorrhizal (AM) fungi are key components of agricultural soil–plant systems, which may be affected by agricultural practices. In organically managed (ORG) orchards, nutrients are supplied in the form of compost, and weeds are suppressed with mulches, whereas synthetic fertilizers and herbicides are used for these respective purposes in conventional (CON) orchards. The effects of ORG and CON orchard floor management practices on native AM fungi in apple orchards were investigated in a randomized field trial. AM root colonization, spore abundance, infectivity potentials and soil glomalin contents were determined in the 0–30 cm soil depth interval, in tree rows, over consecutive seasons. Root colonization was higher in the ORG than the CON treatments, but intermediate where straw mulch was substituted for green work-row covers. Glomalin levels were not affected by the treatments. Root colonization by AM fungi increased with increasing soil pH, P, C, K, Zn, and Mn concentrations, but were suppressed by Cu. Colonization correlated positively with leaf P, Ca and Mg, and with stem circumference, but negatively with leaf N and yield. ORG orchard floor management practices therefore, promoted functional AM associations more effectively than CON practices.
- Full Text:
- Date Issued: 2015
Effect of post-slaughter handling on physico-chemical and microbiological quality of red meat along the distribution chain in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
- Authors: Rani, Zikhona Theodora
- Date: 2015
- Subjects: Meat -- Microbiology Meat -- Transportation -- South Africa -- Eastern Cape Meat -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2490 , vital:27875
- Description: The broad objective of the study was to investigate the effect of post-slaughter handling in the distribution chain on red meat quality and safety. A survey was conducted among 300 consumers and 100 meat handlers in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi) in the Eastern Cape Province of South Africa to investigate their perceptions on meat quality and safety, together with challenges faced by meat handlers during the distribution of meat from the abattoir to retailers. The microbiological profile and physico-chemical quality of red meat at different stages of the abattoir to retail outlets in the distribution chain were also determined. Swabs (n=216) and meat samples (n=450) were collected from beef, pork and mutton carcasses during the loading process of carcasses into trucks at the abattoir, when offloading carcasses at the supply points and during marketing. Physico-chemical qualities such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at each point. To determine the microbiological profiles of the carcasses, four microbiological parameters were considered: Total bacteria count (general bacteria), coliform count (related to hygiene and indicator for pathogens), Escherichia coli (Gram-negative pathogen) and Staphylococcus aureus (Gram-positive pathogen). Two types of packaging (vacuum and overwrapping) were used to determine their effect on shelf-life and microbiological quality of red meat under the normal marketing conditions over a storage duration of 15 days. The results from the study showed low awareness of consumers about the pathogenic diseases which arise from meat. A strong significant association (p ˂ 0.05) between educational status and awareness on meat safety was observed. Most of the consumers perceived that quality goes beyond safety such that 35.6 percent of the respondents indicated that they did not have a problem with consuming spoiled meat, whilst the remaining 64.4 percent indicated that they would r eject spoiled meat. Although retailers indicated that they take meat safety into consideration in their shops, 92 percent of the retailers revealed that they do not perform microbial assessment of meat in their shops. A series of loading and off-loading, temperature fluctuations, environmental temperatures and ques during offloading were reported as the major challenges during transportation of carcasses from the abattoir to the supply points. The microbial counts were significantly (p<0.05) higher in samples from the commercial abattoir than in those from the communal abattoir. Escherichia coli was the predominant microbial contaminant in the samples from both abattoirs. When following the chain, total bacterial count (TBC), coliform count (CC) and the levels of E. coli contamination increased progressively between the loading and the off-loading points (5.1 to 7.9 log10 CFU/cm2; 5.0 to 5.6 log10 CFU/cm2 and 2.7 to 3.7 log10 CFU/cm2, respectively). The storage period, meat type, distance during transportation and temperature were found to have a significant impact on the microbial levels during the distribution of carcasses. Distribution stage had a significant effect (p<0.05) on some of the physico- chemical meat quality attributes and differences in the lightness (L*) and redness (a*) values between the loading, off-loading and display points were observed. Consumers perceived retailer class as one of the factors influencing meat quality, but according to the instrumental measurements retailer class did not have a significant effect on physico-chemical meat quality. However, distance and storage duration significantly (p<0.05) affected (L*) and (a*) values in the meat during distribution chain. Vacuum and overwrapping packaging significantly affected (p<0.05) the shelf life of meat. Therefore, it was concluded that post-slaughter handling during the distribution chain affects the physico- chemical, microbiological and shelf-life of meat.
- Full Text:
- Date Issued: 2015
Effect of temperature on development of the blowfly, Lucilia cuprina (Wiedemann)(Diptera: Calliphoridae)
- Kotzé, Zanthé, Villet, Martin H, Weldon, Christopher W
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442116 , vital:73960 , https://doi.org/10.1007/s00414-015-1153-y
- Description: The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.
- Full Text:
- Date Issued: 2015
- Authors: Kotzé, Zanthé , Villet, Martin H , Weldon, Christopher W
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442116 , vital:73960 , https://doi.org/10.1007/s00414-015-1153-y
- Description: The blowfly Lucilia cuprina is a primary colonizer of decaying vertebrate carrion, and its development provides a temperature-dependent clock that may be used to estimate the post-mortem interval of corpses and carcasses in medicolegal forensic investigations. This study uses the development of L. cuprina raised on a substrate of chicken liver at six constant temperatures from 18 to 33 °C to calibrate a thermal accumulation model of development for forensic applications. Development was optimal near 24 °C; above this temperature, survival of post-feeding life stages was increasingly compromised, while below it, development was increasingly retarded. The lower developmental threshold (~12 °C) and thermal summation constants of L. cuprina are distinct from those reported for Lucilia sericata, verifying that it is essential to identify African Lucilia specimens accurately when using them to estimate post-mortem intervals.
- Full Text:
- Date Issued: 2015
Effect of Tenebrio molitor larvae as a protein source on growth performance, carcass yield and meat quality of broiler chickens
- Authors: Mngqi, Sinethemba Census
- Date: 2015
- Subjects: Broilers (Chickens) Chickens -- Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2622 , vital:27944
- Description: This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.
- Full Text:
- Date Issued: 2015
- Authors: Mngqi, Sinethemba Census
- Date: 2015
- Subjects: Broilers (Chickens) Chickens -- Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2622 , vital:27944
- Description: This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.
- Full Text:
- Date Issued: 2015
Effects of differently shaped silver nanoparticles on the photophysics of pyridylsulfanyl-substituted phthalocyanines
- D'Souza, Sarah, Mashazi, Philani N, Britton, Jonathan, Nyokong, Tebello
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Mashazi, Philani N , Britton, Jonathan , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193564 , vital:45348 , xlink:href="https://doi.org/10.1016/j.poly.2015.06.038"
- Description: This paper reports on the photophysical behavior of (2-pyridylsulfanyl)phthalocyaninato zinc(II) and 2,9(10),16(17),23(24)-tetra-(2-pyridylsulfanyl)phthalocyaninato zinc(II) in the presence of differently shaped silver nanoparticles (nanospheres, nanotriangles and nanoflowers). The presence of shaped nanoparticles increased both triplet quantum yields and lifetimes of the tetra-substituted mercaptopyridine zinc phthalocyanine in DMSO. It is apparent from this work that the shape of the silver nanoparticle used is of little consequence in influencing photophysical behavior of the phthalocyanines.
- Full Text:
- Date Issued: 2015
Effects of inoculating Lachnum and Cadophora isolates on the growth of Vaccinium corymbosum
- Mbizabani, Christine, Dames, Joanna F
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
- Date Issued: 2015
- Authors: Mbizabani, Christine , Dames, Joanna F
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444024 , vital:74179 , https://doi.org/10.1016/j.micres.2015.08.005
- Description: The roots of ericaceous plants harbour a diversity of fungal taxa, which confer eco-physiological benefits to the host. Some of the fungi have been established to form ericoid mycorrhizal (ERM) associations and enhance plant growth in certain ericaceous genera. Although, Lachnum and Cadophora isolates have frequently been identified from the roots of this family, the status of their association and functional roles is still vague. The aims of this study were to identify Lachnum and Cadophora isolates; determine the root-fungal interactive structures formed in associations with Vaccinium corymbosum L. (blueberry) hosts and to examine inoculation effects of the fungal associates using several varieties of the blueberry. Lachnum and Cadophora were isolated and identified from Erica cerinthoides L. and Erica demmissa Klotzsch ex Benth using morphological and molecular techniques. Micropropagated blueberry varieties (Bluecrop, Elliott, Spartan, Chandler and Brightwell) were inoculated with respective fungi and plant growth evaluated. Both fungi colonised the roots and did not have any pathogenic effect.
- Full Text:
- Date Issued: 2015
Effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descripts cattle
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
- Date Issued: 2015
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
- Date Issued: 2015
Effects of political instability in development in South Sudan
- Authors: Annan, David
- Date: 2015
- Subjects: Political stability -- Africa -- History , Economic development -- Political aspects , Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9184 , http://hdl.handle.net/10948/d1020190
- Description: The signing of the Comprehensive Peace Agreement (CPA) between the Republic of Sudan represented by the National Congress Party (NCP) and the SPLM (Sudan People’s Liberation Movement) which represented the people of the Southern part of Sudan in January 2005 ushered in a rare era of peace and hope for the rebuilding and construction of the war ravaged South Sudan. Coupled with the attainment of Independence for South Sudan through an internationally supervised referendum in January 2011, the objectives of years of struggle by the people of the formerly semi-autonomous region were completed. From 2005 until after the independence of South Sudan however, a period that initially was marked by huge euphoria and broad based anticipation of development boom, the support from both local and international actors for the struggle and the plight of the people of South Sudan is waning and at worst has now turned into despair and hopelessness. After attaining independence in 2011, the highest party organ, the Political Bureau decided to remove candidates who were popularly voted by their constituents and replaced them with their cronies, leading to mass exodus of cadres from the party. On top of that, the wide believe that the elections were rigged for SPLM candidates at the expense of the Independent candidates led to another wave of exodus and open rebellion by many veteran cadres of the movement. Today, these rebellions coupled with some complex problematic societal issues are major concern and a source of political instability and violence in some parts of the country. Secondly, the hasty process of the Disarmament, Demobilization, and Reintegration (DDR) campaign, which in some cases were forcefully done left some communities exposed and venerable to attacks by rival communities. This continue to exacerbate and ignite tribal hatred, tension and stereotypes between communities especially in the traditionally volatile parts of the country that are known for cattle rustling and tribal rivalry as a form of cultural practice. Unresolved post secession issues within the SPLM had resulted to political instability and violence thus having negative economic consequences for South Sudan and all the gains the country had made in the past few years vanished after December 15 2013 political upheaval. This thesis will examine the effects of these mentioned complex political instability and economic dilemma South Sudan is being confronted with in the face of the fact that it is still in the process of nation building having attained its Independence only in July 2011.
- Full Text:
- Date Issued: 2015
- Authors: Annan, David
- Date: 2015
- Subjects: Political stability -- Africa -- History , Economic development -- Political aspects , Africa -- Politics and government
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:9184 , http://hdl.handle.net/10948/d1020190
- Description: The signing of the Comprehensive Peace Agreement (CPA) between the Republic of Sudan represented by the National Congress Party (NCP) and the SPLM (Sudan People’s Liberation Movement) which represented the people of the Southern part of Sudan in January 2005 ushered in a rare era of peace and hope for the rebuilding and construction of the war ravaged South Sudan. Coupled with the attainment of Independence for South Sudan through an internationally supervised referendum in January 2011, the objectives of years of struggle by the people of the formerly semi-autonomous region were completed. From 2005 until after the independence of South Sudan however, a period that initially was marked by huge euphoria and broad based anticipation of development boom, the support from both local and international actors for the struggle and the plight of the people of South Sudan is waning and at worst has now turned into despair and hopelessness. After attaining independence in 2011, the highest party organ, the Political Bureau decided to remove candidates who were popularly voted by their constituents and replaced them with their cronies, leading to mass exodus of cadres from the party. On top of that, the wide believe that the elections were rigged for SPLM candidates at the expense of the Independent candidates led to another wave of exodus and open rebellion by many veteran cadres of the movement. Today, these rebellions coupled with some complex problematic societal issues are major concern and a source of political instability and violence in some parts of the country. Secondly, the hasty process of the Disarmament, Demobilization, and Reintegration (DDR) campaign, which in some cases were forcefully done left some communities exposed and venerable to attacks by rival communities. This continue to exacerbate and ignite tribal hatred, tension and stereotypes between communities especially in the traditionally volatile parts of the country that are known for cattle rustling and tribal rivalry as a form of cultural practice. Unresolved post secession issues within the SPLM had resulted to political instability and violence thus having negative economic consequences for South Sudan and all the gains the country had made in the past few years vanished after December 15 2013 political upheaval. This thesis will examine the effects of these mentioned complex political instability and economic dilemma South Sudan is being confronted with in the face of the fact that it is still in the process of nation building having attained its Independence only in July 2011.
- Full Text:
- Date Issued: 2015
Effects of ZnO nanohexagons and nanorods on the fluorescence behavior of metallophthalocyanines
- D'Souza, Sarah, Moeno, Sharon, Nyokong, Tebello
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015
- Authors: D'Souza, Sarah , Moeno, Sharon , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189741 , vital:44927 , xlink:href="https://doi.org/10.1016/j.poly.2014.09.012"
- Description: This paper looks at the fluorescence behavior of zinc phthalocyanines: 2,(3),9(10),16(17),23(24)-tetrakis- (mercaptoacetic acid phthalocyaninato) zinc(II) (ZnTMAAPc), 2,(3),9(10),16(17),23(24)-tetrakis-(mercaptopropanoic acid phthalocyaninato) zinc(II) (ZnTMPAPc) and (OH)AlPcSmix (the latter contains a mixture of the di-, tri- and tetra-sulfonated derivatives with an average of three sulfonated groups per molecule) in the presence of ZnO nanoparticles. Fluorescence lifetimes of Pc complexes generally decreased in the presence of ZnO nanoparticles, with generally longer lifetimes for ZnO nanohexagons compared to ZnO nanorods.
- Full Text:
- Date Issued: 2015